What Causes Excessive Engine Oil Pressure in a Car?
3 Answers
Reasons for excessive engine oil pressure in a car: 1. The viscosity of the oil is too low; 2. The oil strainer screen or oil filter element is clogged; 3. The spring force of the pressure relief valve or return oil valve is weakened or broken, or the sealing surface of the valve is not tight, causing oil leakage and pressure relief; 4. Excessive clearance in the main bearings or connecting rod bearings; 5. Poor performance of the oil pump. Functions of engine oil: 1. Lubrication; 2. Assisting in cooling and temperature reduction; 3. Cleaning and purification; 4. Reducing gas leakage and preventing external pollutants from entering; 5. Preventing contact between water, air, acidic substances, and harmful gases with parts; 6. Shock absorption and cushioning; 7. Reducing wear caused by abrasive particles, surface fatigue, and adhesive wear.
That day I was driving on the highway when suddenly the oil pressure warning light came on, which really scared me. After checking, I found there could be many reasons, the most common being the oil viscosity being too high. If the oil you're using is too thick or doesn't meet the required grade, the oil pressure can spike during cold starts in winter. It could also be a faulty oil pump, such as excessive wear on the pump core causing uncontrolled output pressure; or a broken pressure relief valve, which is supposed to regulate pressure—if it gets stuck, the oil pressure can skyrocket. Another common issue is clogged oil passages, like when the filter is completely blocked by debris, increasing resistance and reducing oil flow. These issues not only trigger the warning light but can also damage seals and cause oil leaks. I suggest not ignoring this—first, pull over and check the gauge readings. If the pressure is indeed too high, immediately check the oil type or take it to a repair shop, otherwise, it could harm the engine. Using season-appropriate oil and regular maintenance can help prevent these problems.
When experienced drivers discuss oil pressure issues, I often hear that excessive pressure is usually caused by several common reasons. First, using the wrong oil viscosity, like a high summer-grade oil in winter, can lead to poor flow at startup, causing pressure spikes. Second, problems with the oil pump, such as internal component damage, can result in uncontrolled output. Third, a malfunctioning pressure relief valve, where the small valve gets stuck, prevents pressure regulation. Fourth, a clogged oil filter or obstructed oil passages increases resistance, naturally raising oil pressure. Another often-overlooked factor is cold starts—initial thick oil can cause higher-than-normal pressure, but it should stabilize quickly. If pressure continues to soar, it could indicate low oil levels or system abnormalities. Such faults can increase engine load, leading to oil seal leaks or component wear. Early troubleshooting is better than post-failure repairs—start with the basics, like checking oil grade and replacing the filter.
